assertion  retraction  graph  subject    predicate        object    datatype    annotation
1          0           graph  DOID:687   oio:id           DOID:687  xsd:string  
1          0           graph  DOID:5789  rdfs:subClassOf  DOID:687  _IRI        
1          0           graph  DOID:5798  rdfs:subClassOf  DOID:687  _IRI